Dr. Karen Santa Cruz of the University of Minnesota examines one of the 670 brains in the Nun's Study, looking for signs of dementia. The brain pictured here is more than 75 years old and still looks healthy says Dr. Santa Cruz. (photo: Lorna Benson/MPR News)

Looking for a research project, David Snowdon became interested in the convent after a graduate student, a former nun, told the young epidemiologist about a retired community of nuns living out their days in Mankato, Minnesota. These women turned out to be ideal for research into aging because of their similarities in lifestyle. Snowdon didn't know exactly what he was going to find among these nuns, but struck gold when finding their personal records in an old olive green file cabinet. The biographical essays they wrote as young women in their early 20s held clues to the way they aged over 50 years later.

What Snowdon found was a correlation between low grammatical complexity in their writing and low "idea density" among sisters who had Alzheimer's disease. An example of a low-scoring sample:

"My father, Mr. L.M. Hallacher, was born in the city of Ross, County Cork, Ireland, and is now a sheet-metal worker in Eau Claire."

On the other hand, a high-scoring essay looks more complex:

"My father is an all-around man of trades, but his principal occupation is carpentry, which trade he had already begun before his marriage with my mother."

These high-scoring writers avoided dementia in their later years and performed better on other cognitive tests. Later, Dr. Snowdon pursuaded the nuns to donate their brains to science. Among the participating nuns who died, none of the high-density ideas nuns' brains showed evidence of Alzheimer's disease, while it was physically present in all of those with low idea density.

Researchers at the University of Minnesota now carry this research forward, trying to figure out why some of the nuns' brains look diseased post-mortem, but before death, these women managed to live out their final days without dementia.

Could there be a protective quality to maintaining your linguistic skills? Or is it that these nuns have always had a bit extra reserve of cognitive ability to weather the ravages of aging? Thankfully, this research provides more insights into questions like these as this massive longitudinal study involving over 600 nuns continues.

Reflections

Idea density. Sounds like a nice way to describe what I call my high level functioning ADD condition! Next time I lose my keys because I am doing three things at once and thinking about 4 more, I will remind myself that it reflects brain health!

Check out the "Vanishing Words" episode of Radiolab (May 5, 2010, http://www.radiolab.org/blogs/... for an interesting discussion of this study. Sister Alberta Sheridan, one of the participants, reads her decades old essay. The piece also includes an exploration of the idea density phenomenon related to the work of Agatha Christie.

Studies have also shown that people with brain damage from various sources can "retrain" their brain by challenging it to learn new things, and that the very process of learning new things somehow triggers the recall of lost abilities. I can attest to this, as I suffered severe cognitive disruption (along with other neurological and physical deficits) as a result of a prolonged battle with untreated Lyme disease, which I had for 16 years before being diagnosed and treated. I'd become bedridden and isolated, unable to interact with more than one person at a time, and then only for brief periods. An outing took special planning.

When I was finally correctly diagnosed, and began aggressive treatment, I had to learn to walk and to read again. My short term memory was very poor and entire chunks of my past were inaccessible to me. I began with simple memory exercises, and then to more complex ones, and gradually my brain reforged neuronal connections to reclaim what I thought I'd lost. Eventually, I went back to work part-time as a field scientist in an area different from the one I'd been in, a pure joy in learning and thinking and analyzing. I picked up the art I'd left behind as a young mother, and learned fused glass, something I'd never done before, then returned to painting. Now retired, I recently took up weaving and am about to learn to spin, for the pure pleasure of learning and because I love doing things with my hands. I volunteer in my community as advocate for others with Lyme disease, and as a volunteer driver for people needing transportation.

My first language is English, and during my illness, I lost two other languages I was fairly competant in, Spanish and French. I am now relearning Spanish, and am thinking of starting another language (maybe Sanscrit) to truly challenge my brain. We lose what we have (or sometimes don't regain it after an event that disrupts brain functioning) because we don't use it. As children, we work very hard to learn. Then it is assumed that we are done, and our brains begin to atrophy. Having already been in that dim world where my brain struggled to stay in touch, I rejoice that I was finally diagnosed and treated and that I have had the opportunity to regain the use of my brain through its natural ability to heal and recreate neuronal connections.

Reading this made me think of hearing, a few years back, about Iris Murdoch's diminishing vocabulary in her later work--which has been seen as an early sign of the Alzheimer's she was ultimately diagnosed with. http://www.telegraph.co.uk/new...Surely, Ms. Murdoch would have been a high density linguist?

Great article, just one thought concerning their fascinating research...What about people not unlike Ronald Reagan, Norman Rockwell, and Pat Summit - all have Alz, and fall into the high-density category. Encouraging and worthwhile research, but there are so many diagnosed with Alz symptoms who don't reflect those findings. Still, I'm encouraged by their efforts that they will help solve this complicated puzzle.

Well, I had no doubt about all that. Use it or lose it.... knowledge, ideas, challenges all tax the brain which I think of as a muscle. If you exercise you also maintain your stability into old age as well so.... there you are, something to do as the days pass along.

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Well,Susan! What a great article and commentaries/photos and insights to help us all keep researching ways to understand how we can enhance our brain-function even when getting over age seventy plus plus..and share to others;many thanks.Its a joy for me to follow up this study.

My father is suffering from medium stage alzheimers. He fits the 'low density idea and grammatical' theme. I remember him as a quiet man and characterized him all my life as an uninvolved father and held it against him because I spent 29 years unhappily married to a man just like him. He had low interest in developing himself and just seemed content with what was. My mother was the opposite; high density idea and complex verbiage type of person. Their's was an unhappy union. Now, six years after her death from the ravages of kidney disease, his mind is slowly deteriorating without her energy to sustain him, but he is expressing himself more, asserting his wishes to be autonomous as my siblings want to force him into a assisted living before he really needs it. I don't recognize this man whom I called "Dad" and all the mental constructs I have formed about who he was are crumbling as he releases all he has wanted to do or say over eight decades of living in fear of speaking his mind. Ah yes, his mind, which has compassionately turned on him for the neglect and disuse by atrophying, causing him to forget all the bad stuff; his illness creating a safe space in which the dark, thick curtains of fear that smothered his soul can now be peeled away without recrimination. I've forgiven him, no, I have come to a place to thank him for my life lessons and hope that he will pass as he lived, peacefully in the comfort of familiar surroundings that are so important to his happiness.